1. Field of the Invention
The present invention relates to a microwave integrated circuit which is of the planar type, but has at least one mesa type semiconductor component of the mesa type. It also concerns a method for the fabrication of this microwave integrated circuit.
2. Description of the Prior Art
The materials on which the invention can be applied are group III-V type materials, such as GaAs, AlGaAs or InP, although it is not restricted to these materials. It can also be applied on silicon since certain silicon diodes of the PIN, IMPATT or other types operate at up to 100 GHz and beyond.
It is known that, in the field of microwave frequencies, mesa components, namely components having a vertical structure with exposed flanks, are the most efficient ones. However, owing to the frequency itself, these components are very small in size, and it is difficult and complicated to assemble them on a ceramic or dielectric (semi-insulating GaAs for example) substrate to make a circuit therefrom. If these mesa components are integrated into a planar integrated circuit, first of all they jut out on the circuit, and this does not facilitate subsequent masking and metallization operations for example and, secondly, their connection through the upper face of the mesa requires additional operations so that the connection metallization on the mesa does not short-circuit the semiconducting layers on the flanks of the mesa.